Well packers



Oct. 7, 1958 R. L. HOLLOWAY WELL PACKERS 2 Sheets-Sheet 1 Filed Jan. 15,1957 INVENTOR.

A ITOR/VE VJ Oct. 7, 1958 R. L. HOLLOWAY WELL PACKERS 2 Sheets-Sheet 2Fi led Jan. 15, 195'? Aria/aver United States Patent WELL PAUKERS RobertL. Holloway, Snyder, N. Y., assignor to American Iron 8.; Machine WorksCompany, Inc, Qldahoma fiity, Ulrla, a corporation of DelawareApplication January 15, 1957, erial No. 634,269

3 Claims. (Cl. 166 118) a This invention pertains to well packers.

1. The principal object of the invention is to provide a well packerwhich can easily be released or unset fol- I lowing setting of thepacker.

The invention may be used both with sleeve type packers and cup typepackers but is particularly applicable to the latter.

For a description of a preferred embodiment of the invention referencewill be made to the accompanying drawings wherein:

Figure 1 is an elevation, partly in section, showing a well packer in awell casing, the packer being unset;

Figure 2 is a view similar to Figure 1 showing the packer in setcondition; and

Figure 3 is a view similar to Figure 1 showing a modification.

Referring to Figure 1, there is shown a well casing in which is disposeda well packer including a tubular mandrel 11 having a conical downwardlytapering packer expander cone 12 thereon. The mandrel 11 is made ofsteel or other similar metal, as is the cone 12 thereon. However, thecone 12 is coated with a thin layer 13 of Teflon, i. e.,tetrafiuorethylene. The Teflon coating may have a thickness preferablyof 0.005 to i 0.010 inch. I

Axially slidably mounted on the packer mandrel 11 is a support 20, tothe upper end of which is screwed a I collar 21 to retain thereon apacker cup 22. The packer cup is preferably made of oil resistantnatural or syn- 1 thetic rubber compound which may be reinforced withfabric or other flexible material. The lower end of the 1 cup issupported on the inside by a steel ring or sleeve 23. The upper end ofthe cup is supported on the outside by a steel ring 24. Support isprovided on its lower end with a slip expander cone 30 to engageslips 31forming parts of a conventional hook wall means for engaging the casing10 to support the packer. As shown, the slips are piv otally connectedto links 32 which in turn are pivotally connected to slip control ring33. Slip control ring 33 normally rests on stop ring 33A secured to themandrel 11 and is connected to bow springs 34 to frictionally engage thecasing 10. The lower ends of the springs are connected to a ring 35which normally is prevented from sliding upwardly relative to mandrel Mby a key 36.

Upon slight upward movement of the mandrel (the springs 34 holding ring35 stationary) followed by a quarter turn to the left, the key 36engages stop 37 and is thus aligned with a slot 38 in ring 35 whereupondownward movement of the key 36 through ring 35 is possible. Downwardmovement of the mandrel causes cone 12 to engage cup 22 and drive cone30 into slips 31 which are held stationary in the casing by springs 34.i The cone forces the slips to move radially into engagement with thecasing.

2,855,051 Patented Got. 7, 1958 After the slips have set, that is,gripped the casing with their teeth 40 to prevent axial movement of theslips relative to the casing, further downward motion of the mandrel 11forces cone 12 into packer cup 22 to expand it radially into sealingengagement with the casing, the position shown in Figure 2. Thepreferred particular shape of the packer cup, part tapered and partstraight, is more fully described in United States Patent 2,356,232 toFitzpatrick. I

The force required to set the packer, that is, to expand cup 22 intosealing engagement with the casing and to retain the packer in positionagainst well pressure therebelow, may be of order of ten thousandpounds, this force being obtained by placing on the mandrel all or apart of the weight of the well tubing connected to the upper end of thepacker mandrel. Normally after a packer has been once set considerabledifficulty is experienced if it is ever desired to unset it to retrieveit from the well or reset it in a different position. A considerablepart of this difficulty arises because the packer cup sticks to thepacker expander cone. By virtue of the Teflon coating on the packerexpander cone in accordance with the invention, this difliculty isovercome.

As previously stated, the invention may also be used with a conventionalsleeve type packe in which the packer sleeve is compressed between astop on the packer mandrel and a support such as the hook wall meansherein described. In such case the Teflon coating would be disposed onthe mandrel inside the sealing member of the packer as in the abovedescribed embodiment, the difference being that in this case the sealingmember is a sleeve rather than a cup and the mandrel does not have aconical packer expander portion. Such a construction is shown in Figure3.

While a preferred embodiment of the invention has been shown anddescribed, many modifications of the invention can be made by oneskilled in the art without departing from the spirit thereof and it isdesired to cover by Letters Patent all forms of the invention fallingwithin the scope of the following claims.

What is claimed is:

l. A well packer including a tubular mandrel, a rubber sealing meanstherearound, and means to expand said member to seal between the mandreland a well casig, said madrel having an outer surface composed of Teflonreleasably engaging said sealing means when the packer is set.

2. A well packer comprising a tubular mandrel having a packer expandercone thereon, a packer cup of oil resistant rubber compound disposed onsaid mandrel, means to support said cup in a well casing whereby axialmotion of said cone into said cup radially expands said cup, said conehaving a Teflon coating thereon where it engages said cup, wherebywithdrawal of said cone from said cup is facilitated.

3. A well packer comprising a mandrel, annular rubber sealing means onthe mandrel, and means between the sealing means and the mandrel toprevent the sealing means from sticking to the mandrel when the sealingmeans is placed under pressure between the mandrel and a well pipe inwhich the packer is disposed and subjected to the temperature conditionsexistent in a well.

References Cited in the file of this patent UNITED STATES PATENTS2,356,232 Fitzpatrick Aug. 22, 1944 FOREIGN PATENTS 2,488,446Switzerland Nov. 15, 1949

